1. Field of the Invention
The present invention relates generally to cleaning devices utilized to remove deposits and/or contamination from processing chamber walls, tooling and substrates within such chambers and, more particularly, to such devices which utilize a plasma formed within the processing chamber to achieve such cleaning.
2. Discussion of the Prior Art
In the course of many semiconductor device processing steps, unwanted deposits and/or contaminants are formed on the chamber walls of the processing equipment. As these deposits and/or contaminants accumulate in successive runs, they can dislodge from the chamber wall, yielding particulate and/or chemical contamination of the wafers and low die yield. Frequent cleaning of the chamber wall is thus required.
In the past, chamber cleaning usually meant disassembly of the chamber from the equipment and cleaning with corrosive and toxic chemicals. The drawbacks of this method are obvious: long equipment downtimes, high labor costs and loss of process repeatability due to chamber disassembly/reassembly, breakage and/or degradation of the chamber and other equipment parts due to diassembly/reassembly and handling, the chemical contamination of the chamber by liquids used to clean it and handling, and safety hazards associated with the use of corrosive and toxic chemicals.
A more recent innovation in the method of cleaning process chambers is that described in commonly assigned U.S. patent application Ser. No. 06/735,821, filed May 17, 1985 now U.S. Pat. No. 4,657,616 for In-situ CVD Chamber Cleaner by David Benzing and others. It describes the use of two or more electrodes placed in the interior of a process chamber or a single internal electrode together with the use of furnace coils or radiant lamp assemblies as an external electrode to create a plasma within the process chamber that effectively cleans the chamber walls. A disadvantage of this apparatus and method is that the electrode structure is fairly large and must be inserted and then removed from the chamber, requiring sufficient access space to the chamber. A further disadvantage is the inability to simultaneously clean the chamber together with any associated tooling.